The nitration of hydrocarbons generally involves the distillation of both an oil phase and an aqueous phase. However, this process requires large energy and capital expenditures.
In conventional vapor phase nitration schemes, described in U.S. Pat. Nos. 3,780,115 and 3,869,253, the reactor effluent is rapidly quenched and the quenched mixture is sent to a separator. The gas phase is then withdrawn for purification and recycling and the aqueous phase and the oil phase are separated by decantation and treated simultaneously to recover the desired nitroparrafin by distillation. New high pressure phase nitration processes use a lower strength nitric acid, resulting in a larger aqueous phase. Processing both the large aqueous phase and the oil phase is very energy-consuming. A need exists, therefore, for more economical and energy efficient processes for the manufacture of nitroalkanes.